Toda!!

 

The main way to do this is to drop the idle RPM down low enough that the car starts to idle choppy. Just go to the idle speed menu in the Engine screen in LT1 edit. I'm sure if you play with the IAC menu and the Cylinder Balance menu.

I don't really know if any of that is a great idea. Idling lower than what is needed and making it rough on purpose only is going to cause problems, fouling up the plugs is one of them. The cylinder balance is really for getting all the cylinders to run at the right A/F ratio which can only be done on a dyno with EGT probes in every exhaust tube.

A cam idles choppy because of the low vaccum at idle. That's directly related to the idle RPM and the overlap. If you can't change the overlap, then change the idle RPM. You can also physically change the air bleed hole in the throttle plates or plate and not let the IAC motor compensate for that.

Bret

 

Hey Brett, I have a feeling Vince has something a little more complicated than this. I have tried to lower the idle to 700 (I keep it around 900). All this accomplished was to make the "bumps" slower. I am looking for the "camming" sound, but much faster - as if the engine were idling faster. Maybe that is a characteristic of a solid roller. I'm not sure because I know --> <-- much about cars, cams, or life in general . I'm guessing his "technique" has something to do with the a:f and/or idle timing. I'm not going to play with it on my car though .

On one hand I'd like to have that fast, attacking kind of cam sound, but on the other hand I like the weenie cam sound mine makes - mainly because the car is such a turd.

FWIW, My idle MAP reading is around 18-19.
Ryan

 

It has not a thing to do with idle speed or IAC menu's. Doesn't Foul plugs either. Its a little trick I picked from Shalin Patel and Brad Brand a few years back. 96 Speed is moving the right direction. It no big deal its just a little thing I keep for myself.

Vince

 

My $.02

I have trapped 122 MPH at both ESTA and NYIRP. I did not see any difference between MPH with both my car and my brothers car.

 

I would have to agree with Jason, your MPH seems low. When I had only a cutout and lid on my car, I always trapped around 107-108+ mph at NYIRP. This was with ****ty 2.2+ 60' times and various weather conditions. I never had it dynoed pre-turbos, but I can't image it being much over 300 rwhp in comparison with comperable LS1's.

 

i also think it depends on the night

i USUALLY run good times, but i went once this spring and man the track was so slippery, i couldn't even cut better than a 2.1 on drag radials (rememer me = fwd )

i guess on test/tune days they dont prep the track as well as they would on an event night?